> On Aug 10, 2022, at 3:08 PM, richard coleman <rcoleman.ascentgl@xxxxxxxxx> wrote: > > I'm currently standing up a number of PostgreSQL 14 servers. There is a question concerning ports and protocols required or used by PostgreSQL. Unfortunately, I can't seem to find any such listing. Most references only mention the primary connection port, ex: tcp 5432. There is whatever port you configure it for; the default is 5432. > Apparently, I've discovered that PostgreSQL connects to itself over UDP. No it doesn't. (It can use Unix domain sockets for local connections.) > I've also discovered, while looking at the network while one of our server was running PostgreSQL, that while there were a number of connections between local 5432 and a random remote port, there was also a connection from a local random port to a remote 5432. If these ports were closed and only 5432 left open, this connection would have failed. That sounds like you're confused by the fact that when a client connects to a server, the server port is fixed, but the client chooses a random outbound port. > Does anyone know where I might find the definitive listing of ports and protocols used by PostgreSQL? TCP, whatever port you configure it listen on.